code: def test_annotations(lut):
      assert lut.annotations == {}
      anno = {0: "low", 0.5: "medium", 1: "high"}
      lut.annotations = anno
      assert lut.annotations == anno
  
imports: import numpy
  import pytest
  import vtk
  import pyvista
  from pyvista import Color, LookupTable
label_desc: Use image node_id 8 for calling a global function with example usage: test_annotations(lut) without return types